Initial commit

1 files changed, 94 insertions, 0 deletions

diff --git a/awsauth.py b/awsauth.py
new file mode 100644
index 0000000..7ddac4f
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+++ b/awsauth.py
@@ -0,0 +1,94 @@
+import base64
+import hmac
+import urllib

+from hashlib import sha1 as sha
+from urlparse import urlparse
+from email.utils import formatdate
+from requests.auth import AuthBase
+
+class S3Auth(AuthBase):
+    # List of Query String Arguments of Interest

+    special_params = ['acl', 'location', 'logging', 'partNumber', 'policy',

+                       'requestPayment', 'torrent', 'versioning', 'versionId',

+                       'versions', 'website', 'uploads', 'uploadId',

+                       'response-content-type', 'response-content-language',

+                       'response-expires', 'reponse-cache-control',

+                       'response-content-disposition',

+                       'response-content-encoding']

+
+
+    """Attaches AWS Authentication to the given Request object."""
+    def __init__(self, access_key, secret_key):
+        self.access_key = str(access_key)
+        self.secret_key = str(secret_key)
+
+    def __call__(self, r):
+        #Create date header if it is not created yet
+        if not r.headers.has_key('date') and not r.headers.has_key('x-amz-date'):
+            r.headers['date'] = formatdate(timeval=None, localtime=False, usegmt=True)
+        r.headers['Authorization'] = 'AWS %s:%s'%(self.access_key, self.get_signature(r))
+        return r
+
+    def get_signature(self, r):   
+        h = hmac.new(self.secret_key, self.get_canonical_string(r), digestmod=sha)

+        return base64.encodestring(h.digest()).strip()
+
+    def get_canonical_string(self, r):

+        parsedurl = urlparse(r.url)
+        objectkey = parsedurl.path[1:]
+        query_args = parsedurl.query.split('&')
+        #Sort alphabetical
+        query_args.sort()
+        bucket = ''
+        if len(parsedurl.netloc.split('.')) == 4:
+            bucket = parsedurl.netloc.split('.')[0]
+        if len(parsedurl.netloc.split('.')) == 3 and parsedurl.netloc.split('.')[0].lower() != 's3':
+            bucket = parsedurl.netloc.split('.')[0]
+        
+        interesting_headers = {}

+        for key in r.headers:

+            lk = key.lower()

+            if r.headers[key] != None and (lk in ['content-md5', 'content-type', 'date'] or

+                                         lk.startswith('x-amz-')):

+                interesting_headers[lk] = r.headers[key].strip()

+    

+        # these keys get empty strings if they don't exist

+        if not interesting_headers.has_key('content-type'):

+            interesting_headers['content-type'] = ''

+        if not interesting_headers.has_key('content-md5'):

+            interesting_headers['content-md5'] = ''

+    

+        # If x-amz-date is used it supersedes the date header.

+        if interesting_headers.has_key('x-amz-date'):

+            interesting_headers['date'] = ''

+                    

+        sorted_header_keys = interesting_headers.keys()

+        sorted_header_keys.sort()

+    

+        buf = "%s\n" % r.method

+        for key in sorted_header_keys:

+            val = interesting_headers[key]

+            if key.startswith('x-amz-'):

+                buf += "%s:%s\n" % (key, val)

+            else:

+                buf += "%s\n" % val

+    

+        # append the bucket if it exists

+        if bucket != "":

+            buf += "/%s" % bucket

+    

+        # add the objectkey.  even if it doesn't exist, add the slash

+        buf += "/%s" % urllib.quote_plus(objectkey)

+    
+        params_found = False

+        # handle special query string arguments
+        for q in query_args:
+            k = q.split('=')[0]
+            if k in self.special_params:
+                if params_found:
+                    buf += "&%s"%q
+                else:    
+                    buf += "?%s"%q
+                params_found = True              
+        return buf       
+